Modern lifestyle is undergoing one of the most fundamental changes in decades, thanks to quick emergence of a mobile computing paradigm. The first phase of this trend brought the proliferation of smartphones and tablets. According to market statistics and forecasts, smartphones and tablets have outsold personal computers for the first time in the fourth quarter of 2011. Three years later, in the fourth quarter of 2014, the unit shipment volume of tablets alone is expected to exceed cumulative personal and business PC shipments, and by 2017, about 87% of the market share of smart connected devices will belong to smartphones and tablets, compared with 13% for desktop and mobile PCs. In response to growing volumes and expanding features sets of smartphones and tablets, a new generation of mobile software applications has emerged that utilize enhanced smartphone connectivity, take advantage of their content capturing capabilities via embedded cameras, microphones, handwritten input, make use of device motion sensors, multi-touch screens, etc.
Another trend in mobile application development is the result of the multi-platform co-existence of PCs, smartphones and tablets. With four major PC and mobile platforms—Windows, Mac, iOS and Android—running on billions of end user devices with vastly different hardware and software characteristics and form factors, developers are increasingly improving multi-platform applications. Since many current users own both PCs and smartphones, quick proliferation of multi-platform content management applications, such as the Evernote service and software developed by Evernote Corporation of Redwood City, Calif., is suggesting a strong usage case for cloud-based personal information management applications. This trend also underscores the demand for multi-platform user interfaces. Massive market experiments indicate that users strongly prefer multi-platform user interfaces that deliver the best experience on each particular platform rather than a scrupulous feature and UI parity across different platforms. Thus, Evernote client software follows user interface styles and guidelines adopted on each platform; even devices with different form factors on the same platform, such as iPhone and iPad, may employ different Evernote user interface designs and layouts. Still, some essential similarities of UI metaphors on high resolution screens with touch interfaces and ways of interaction with application elements and outlines on various platforms induce similarities in multi-device application usage and UI.
However, even the aforementioned reduced similarity in usage patterns for multi-platform application may disappear in the near future. The next wave of mobile computing is broadly associated with multi-purpose and specialized mobile devices, especially wearable computers, such as smart bands, smart watches, smart glasses and other head-mounted cameras and displays, intelligent and adaptable clothes, wearable medical devices, etc. In 2014, wearables shipments are expected to exceed 20M units, a 129% growth from 2013, dominated by smart watches and smart bands (wrist band, arm band, head band activity trackers). According to market forecasts, about 250 million wearable devices will be in use by 2018, with annual shipments reaching 135 million units and the cumulative volume of sales of wearable devices in 2014-2018 exceeding 370 million units. Wrist-worn devices, such as smart watches and wristbands for activity tracking and medical purpose, are expected to retain their domination of the early wearables market. Some analysts project the market share of wrist-worn wearables to reach 87% of all wearable shipments in 2018.
As a result of the ever expanding mobile market, software applications may adapt by running in parallel on multiple devices of the same owner, with vastly different control, display, data capture and connectivity features, form factors and other parameters. In fact, the role of application replicas on various devices may depend on specialized capabilities of the devices running the applications, such as a broad spectrum of connectivity and input options on smartphones, instant hands free access to data on smart watches and smart glasses, seamless biometric user authentication capabilities of body sensors such as wristbands, etc.
In addition to the above differences between application features and usage on diverse mobile devices, the devices may interact with other software and mobile networks, such as a car or enterprise or home control systems running on an even broader set of devices. Accordingly, personal mobile devices may have different means of interacting with extended mobile networks, which leaves an even smaller space for common, unified user interfaces.
Accordingly, it is desirable to design new distributed feature sets and user interfaces for software applications simultaneously running on multiple interconnected mobile devices located on or with a user.